Pressurized infusion device and liquid cooling system

1. A pressurized infusion device, comprising: a liquid storage tank having a first end and a second end opposite to the first end; a pump connected with the first end of the liquid storage tank and having a first connecting port, a second connecting port, a third connecting port and a fourth connecting port, wherein a pump flow channel from the first connecting port to the second connecting port is formed inside the pump, and a bypass flow channel from the third connecting port to the fourth connecting port is also formed inside the pump; a first cap, covering the second end of the liquid storage tank and having a first through hole and at least one second through hole, wherein the first connecting port is communicated with the first through hole via an infusion pipe disposed outside the pump; wherein the first end is located at the top of the liquid storage tank and the second end is located at the bottom of the liquid storage tank; and a pipe disposed in the liquid storage tank connected to the second connecting port and extending from the second connecting port to a bottom portion of the liquid storage tank which is adjacent the first cap.

2. The pressurized infusion device of claim 1 , wherein the second connecting port and the fourth connecting port are located at the same side of the pump, and the third connecting port and the first connecting port are indirectly communicated to each other.